Construction and earthmoving vehicles, which utilize endless self-laying track chain assemblies for support and propulsion, generally include a sprocket wheel to engage and drive the track chain. Many different types of sprocket wheels have been used in the past, including a wheel having a plurality of integrally formed teeth, a circular support member for supporting several sprocket segments with each segment having several teeth, and hub members accommodating a plurality of separate, individual teeth. Many of the previous sprocket wheels have included resilient means for isolating and dampening the sprocket wheel noise.
One type of sprocket wheel having a plurality of separate, individual teeth bolted to a hub portion is disclosed in U.S. Pat. No. 2,365,555, issued to H. D. Geyer et al. on December, 1944. In this patent, the teeth are fulcrumed to the hub portion somewhere near the middle of the teeth so the teeth can rotate in either direction about the fulcrum. Resilient means are provided to return the teeth to their original no load position. This arrangement is intended to make the teeth self adjusting to accommodate variations in the track chain.
Another type of sprocket assembly with replaceable teeth is shown in U.S. Pat. No. 4,522,611, issued to D. M. Hiatt on Jul. 1, 1985. This patent discloses a generally cylindrical sprocket hub equipped with a plurality of L-shaped pockets in the periphery of the hub. A replaceable tooth, having a partially T-shaped inner end, is intended to be received within each of the L-shaped pockets and locked in place by wedge lock means, which operate against the T-shape of the tooth.
Each of the above-noted sprocket assemblies provide individual replaceable drive teeth. However, such sprocket assemblies appear to be quite complicated and costly, and utilize intricately formed pieces. The above-noted sprocket assemblies would appear ineffective or quite limited in their ability to reduce noise levels during driving operations against an endless track chain assembly.
The present invention is directed to overcoming one or more of the problems as set forth above.